edit with a bit of explanation: the 3rd overload of the GetData allows you to specify a rectangle to retrieve colours from, so you simply have to make sure your data array is the same size as what your after returning.

Why not just sample the textures from the smallest mip level? That will give you an average colour and won't require anything CPU-side.

It appears that the gentleman thought C++ was extremely difficult and he was overjoyed that the machine was absorbing it; he understood that good C++ is difficult but the best C++ is well-nigh unintelligible.

edit with a bit of explanation: the 3rd overload of the GetData allows you to specify a rectangle to retrieve colours from, so you simply have to make sure your data array is the same size as what your after returning.